Calibration · Evaluation · Decision models

Decision benchmarks leaderboard

Accuracy and calibration of Jev, other hosted decision models and open-weight ones on the decision benchmarks their makers use, broken down by multiple-choice, yes/no and rating questions.

Twenty-three models, fifteen hosted and eight with open weights, all asked the same questions (the exam leaderboard lists them). The benchmarks are the ones AutoTrust and NeoHorse report for their models, scored for calibration as well as accuracy: Kev’s decision-v7, transfer-v4 and transfer-v9 suites, VitaminC and MASSIVE, and the original and easy tiers of JevBench. Every reference answer in the summary comes from people or from rules. Two more benchmarks, JevBench’s hard tier and Nimble, have answers written by language models; they are shown under “Each benchmark” but left out of the summary.

Questions come in three kinds. Multiple choice picks one of several options, yes/no asks whether a statement holds, and rating places something on an ordered scale. Pick a kind to see how each model handles it.

RankModelAccuracy ↑ECE ↓Brier score ↓Over/underconfidence
11 ⊸ 4Perplexity Decider v1.2Perplexity · API only92.7% ±0.9%0.021 ±0.0060.047 ±0.006+0.004
21 ⊸ 4Drex MaxNace AI · API only92.3% ±0.9%0.029 ±0.0080.052 ±0.007+0.021
31 ⊸ 4Perplexity Decider Flash v1.2Perplexity · API only91.0% ±1.0%0.034 ±0.0080.059 ±0.007+0.008
41 ⊸ 4Mercury DecideInception · API only91.4% ±1.1%0.053 ±0.0090.062 ±0.009+0.050
55 ⊸ 10d1-ultraLiquid AI · API only87.2% ±1.4%0.034 ±0.0090.082 ±0.006−0.010
65 ⊸ 12ClefCloudflare · API only87.9% ±1.2%0.048 ±0.0100.083 ±0.008+0.025
75 ⊸ 13Clef OmniCloudflare · API only87.9% ±1.3%0.054 ±0.0100.086 ±0.007+0.004
85 ⊸ 14Clef FlashCloudflare · API only86.6% ±1.4%0.048 ±0.0100.088 ±0.008+0.007
95 ⊸ 14Jev 1.13TypeSafe · API only87.4% ±1.5%0.061 ±0.0110.088 ±0.010+0.051
105 ⊸ 14Jev 1.14TypeSafe · API only86.9% ±1.3%0.061 ±0.0110.089 ±0.009+0.050
116 ⊸ 16JEV-27BAutoTrust AI · Apache-2.086.2% ±1.3%0.066 ±0.0110.097 ±0.009+0.044
126 ⊸ 17JEV-9BAutoTrust AI · Apache-2.083.8% ±1.6%0.055 ±0.0120.100 ±0.009+0.039
137 ⊸ 17JPT-4Bkirp · CC BY-NC 4.084.4% ±1.5%0.065 ±0.0120.102 ±0.010+0.037
148 ⊸ 17Drex v2.0Nace AI · API only84.0% ±1.6%0.073 ±0.0120.103 ±0.008+0.033
1512 ⊸ 18Strands Decider 2BAmazon Strands Labs · Apache-2.082.4% ±1.6%0.067 ±0.0120.115 ±0.009+0.004
1611 ⊸ 18GPT-6 Luna DecisionsOpenAI · API only84.3% ±1.5%0.096 ±0.0130.116 ±0.010+0.082
1711 ⊸ 18Drex v1.5Nace AI · API only83.1% ±1.5%0.092 ±0.0130.117 ±0.011+0.080
1815 ⊸ 18Kev-4BJared Palmer · Apache-2.083.8% ±1.6%0.107 ±0.0130.124 ±0.009−0.025
1919 ⊸ 23Solar DecideUpstage · API only81.3% ±1.7%0.153 ±0.0160.165 ±0.015+0.149
2019 ⊸ 23Open-Jev-2BZefan Cai · Apache-2.073.9% ±2.1%0.109 ±0.0160.165 ±0.009−0.054
2119 ⊸ 23Solar Decide FlashUpstage · API only75.7% ±2.1%0.149 ±0.0170.176 ±0.015+0.134
2219 ⊸ 23Qwen3.5-9B, untrainedAlibaba Qwen · Apache-2.072.0% ±2.2%0.112 ±0.0170.178 ±0.009−0.096
2319 ⊸ 23LayaConvai Innovations · Apache-2.071.6% ±2.3%0.108 ±0.0160.183 ±0.013+0.051

All questions: means over the 4 benchmarks with human or rule-based labels that contain this kind of question. JPT-4B would not answer 89 records across these benchmarks, which its scores leave out. GPT-6 Luna Decisions would not answer 11 records across these benchmarks, which its scores leave out. Solar Decide would not answer 116 records across these benchmarks, which its scores leave out. Solar Decide Flash would not answer 116 records across these benchmarks, which its scores leave out. Ranked by Brier score. Each ± and error bar is a 95% interval from resampling questions, and the small numbers under each rank are the range of ranks those intervals allow. Over/underconfidence is average confidence minus accuracy.

By question type

The same models on multiple choice, yes/no and rating questions. A long line means a model behaves very differently depending on how the question is asked.

0.0000.0500.1000.1500.200Perplexity Decider v1.2Drex MaxPerplexity Decider Flash v1.2Mercury Decided1-ultraClefClef OmniClef FlashJev 1.13Jev 1.14JEV-27BJEV-9BJPT-4BDrex v2.0Strands Decider 2BGPT-6 Luna DecisionsDrex v1.5Kev-4BSolar DecideOpen-Jev-2BSolar Decide FlashQwen3.5-9B, untrainedLaya

Each benchmark

ModelQuestionsAccuracyECENoise floorBrier scoreOver/underconfidenceLog loss
Perplexity Decider v1.23,01285.3%0.0270.0130.086+0.0250.386
d1-ultra3,01285.8%0.0110.0140.090+0.0030.381
Drex Max3,01285.1%0.0410.0120.091+0.0380.379
Drex v2.03,01284.0%0.0340.0170.093−0.0200.412
Mercury Decide3,01285.8%0.0670.0110.094+0.0630.418
Clef3,01284.4%0.0350.0130.100+0.0330.427
Jev 1.143,01283.7%0.0460.0120.104+0.0440.707
Kev-4B3,01280.9%0.0110.0170.104−0.0030.479
Jev 1.133,01284.1%0.0490.0130.105+0.0440.830
Drex v1.53,01281.1%0.0630.0130.106+0.0630.488
Clef Flash3,01282.9%0.0300.0150.107+0.0270.470
Perplexity Decider Flash v1.23,01281.5%0.0440.0140.108+0.0400.478
Clef Omni3,01284.2%0.0440.0140.112+0.0320.483
JEV-27B3,01281.6%0.0310.0160.117+0.0020.526
GPT-6 Luna Decisions3,00181.2%0.0790.0130.121+0.0730.944
JEV-9B3,01277.7%0.0290.0170.126+0.0240.570
JPT-4B2,91078.2%0.0490.0170.129+0.0450.566
Strands Decider 2B3,01274.6%0.0340.0190.144−0.0110.639
Qwen3.5-9B, untrained3,01271.1%0.0440.0210.166−0.0310.736
Open-Jev-2B3,01269.0%0.0390.0200.172+0.0040.795
Solar Decide2,93278.3%0.1620.0090.177+0.1620.916
Solar Decide Flash2,93269.5%0.1550.0150.201+0.1520.874
Laya3,01260.2%0.1330.0200.219+0.1331.466

GPT-6 Luna Decisions would not answer 11 records here, so its scores cover the rest.

Solar Decide would not answer 116 records here, so its scores cover the rest.

Solar Decide Flash would not answer 116 records here, so its scores cover the rest.

JPT-4B would not answer 89 records here, so its scores cover the rest.

Checking our runs against published scores

Clean accuracy on Kev's six partitions, and their mean, the "Kev" score in AutoTrust's and NeoHorse's model cards.

Modeldecision-v7 devdecision-v7 testtransfer-v4 devtransfer-v4 testtransfer-v9 devtransfer-v9 testKev scorePublished
JEV-27B84.282.183.786.977.078.181.9983.75
JEV-9B83.379.781.482.374.072.978.93—
Qwen3.5-9B, untrained75.673.373.077.362.765.571.23—
Kev-4B87.286.581.783.873.473.480.9981.47
JPT-4B83.280.880.283.971.272.478.61—
Strands Decider 2B82.580.872.377.664.066.673.96—
Open-Jev-2B74.472.968.074.258.761.968.36—
Laya66.565.264.865.750.951.960.8161.30

Reliability diagram

What we found

Perplexity’s Decider v1.2 leads, with Drex Max close behind. On these benchmarks it is right more than nine times out of ten, and its confidence tracks its accuracy almost exactly. Jev sits in the middle of the pack here, behind several hosted models it beats on exam questions.

Most models are surer than they should be on fact checks. VitaminC asks whether evidence supports a claim, and nearly every model, Jev included, is overconfident on it. Among hosted models, only Perplexity’s two and d1-ultra stay calibrated on it.

Question type matters. Many models handle yes/no questions well and struggle more with ratings, so a model’s overall rank can hide a weak spot. The chart above shows each model by question type.

How the models were asked

Hosted models were asked through OpenRouter in October 2026, each pinned to its maker’s own servers, with every question in its native form. Open models were run through the servers their authors ship, also with native questions. JEV models answered multiple-choice and yes/no questions through their own decision slots. Their rating slots are a fixed 0 to 5 scale without level descriptions, so rating questions were asked as multiple choice over the level descriptions. We also tried JEV’s rating slots with the descriptions written into the question; that was less accurate for both JEV models (62.1% against 64.9% for JEV-27B, 54.0% against 61.5% for JEV-9B).

What to keep in mind

  • Our scores reproduce the published ones closely, with one exception. Kev-4B and Laya land within half a point of the Kev scores NeoHorse reports. JEV-27B lands 1.8 points below AutoTrust’s figure; the rating format does not explain it, and the likely causes are half precision on our older GPUs and how structured inputs are turned into text.
  • Kev-4B was trained on decision-v7’s training split, so the decision-v7 partitions are in distribution for it.
  • Some hosted models skipped records. Solar Decide and Solar Decide Flash take at most 26 options and could not answer 116 of Kev’s records. GPT-6 Luna Decisions refused 11. Their scores leave those out.
  • JPT-4B’s server could not answer some inputs, mostly conversations stored as lists of messages with a “customer” role. Those records are left out of its scores, and the per-benchmark table says how many.
  • JEV-27B has no results on JevBench’s hard tier or Nimble. Their longest prompts do not fit on our 11 GB GPUs; neither benchmark is in the summary.
  • Only clean questions are scored. Kev’s suites also contain shuffled and “none of these” variants, which are not used here.

Data

Every number on this page comes from these files, under CC BY 4.0.

Changelog

  • Added Jev 1.13, Jev 1.14 and thirteen other hosted decision models; every model is now scored on the same questions.
  • First published.

Discussion

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